1. Field of the Invention
The present invention relates to light-emitting diode (LED) die packages and methods for producing the same, and more particularly, to LED die packages and methods for producing the same with a reduced bin number.
2. Description of the Prior Art
FIG. 31 is a schematic side view of a conventional LED package. FIG. 32 is a schematic diagram showing a bin distribution of LED chips after packaging, in which the light emitted from the LED chips have the same wavelength and the same brightness.
Referring to FIG. 31, the conventional LED package includes an LED chip 91 disposed on a lead frame 90, and a lens 92 formed on the lead frame 90 in a manner covering the LED chip 91.
The electrodes (not shown) of the LED chip 91 are connected electrically to the corresponding legs 900 of the lead frame 90 via wires 93.
It should be noted that a phosphor layer 94 is formed on an electrode-side surface of the LED chip 91. The formation of the layer 94 is achieved by the following steps: coating the electrode-side surface of the LED chip 91 with liquid phosphor layer material and curing the liquid phosphor layer material by a baking process so as to form the phosphor layer 94. However, the convention process for formation of the phosphor layer 94 has the following drawbacks:
1. Uneven thickness—flowing of the liquid phosphor layer material in all directions may occur before performing the baking process and, therefore, the respective phosphor layers 94 formed on the respective LED chips 91 will differ in thickness.
2. Different area—due to the same reason as mentioned in point 1 above, the areas of the respective phosphor layers 94 formed on the respective LED chips 91 will be different.
3. Different shape—due to the same reason as mentioned in point 1 above, the respective phosphor layers 94 formed on the respective LED chips 91 will differ in shape.
4. Relative position offset—due to the same reason as mentioned in point 1 above, the positions of the respective phosphor layers 94 formed on the respective LED chips 91 relative to the corresponding LED chips 91 will be different.
Due to the aforesaid drawbacks, the LED chips which originally emit light with the same wavelength and the same brightness would be unfavorably fabricated into LED chip packages that show a broad variety in terms of color temperature, brightness and wavelength, resulting in the so-called side bins. Referring to FIG. 9 that shows a bin distribution resulted from the drawbacks described above, it should be noted that the LED chips sorted into the same bin will be divided into 128 bins after the packaging process. Normally, only the central 60% of the packages in the distribution are adapted for subsequent use, and the rest 40% are considered as side bins. As a result, the manufacture cost is increased.
Moreover, since the cross-sectional area of the wire 93 is so small that the heat generated by the LED chip 91 can hardly dissipate to the surroundings through the legs 900 of the lead frame 90, the heat would consequently reduce the efficiency of the LED chip package.
In view of the above, R.O.C. Patent Application No. 097118327, entitled “Light-Emitting Diode Die Package and Method for Producing Same” and assigned to the present applicant, was filed previously to serve as a solution to the conventional drawbacks. In order to fulfill the need in this respect, the inventor has further devised a new LED die package and a method for producing the same, as disclosed herein.